


Omiko's Obese Baby

by AndSoISaidMrglrg



Category: Kill la Kill (Anime & Manga)
Genre: ABDL, Diaper, Diapered, Diapers, Dom/sub, F/F, Weight Gain, messing
Language: English
Status: Completed
Published: 2020-10-21
Updated: 2020-10-21
Packaged: 2021-03-08 17:54:26
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,222
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27140705
Author URL: https://archiveofourown.org/users/AndSoISaidMrglrg/pseuds/AndSoISaidMrglrg
Summary: Story for Snakeman. Due to some rather unfortunate metabolism luck, when Ryuko ended up staying with Mako and her family,  the scissor wielding teen put on an extra few pounds. Thankfully, that didn't deter the young girl from fighting, but it did manage to get the attention of a certain Tennis star.
Relationships: Hakodate Omiko/Matoi Ryuuko
Comments: 1
Kudos: 6





	Omiko's Obese Baby

Honnōji Academy, a place where the strong thrive and the weak barely struggle to survive, only to end up as fodder for those at the top if their drive isn’t as high. There were many notable names of those who were at the top of the ladder, but not even the great Satsuki herself could compare herself to the dynamic power couple that ran the school from behind the scenes.

First up was Omiko, the ruthless tennis star with a deadly serve that was sure to knock and pro off their feet, assuming it doesn’t rip off their head first.

Then there was the new girl to the block. She made quite the entrance on her first day, and after finding board with the Mankanshoku family, the young girl found herself making an even bigger entrance the second time around.

When Ryuko walked through the gates the second time, everyone snickered, thinking that it was the same petite girl who got her ass handed to her on a silver platter. None of them could have imagined that over the course of just a single week, that thin girl had transformed into a gargantuan threat that towered over them like a giant boulder just waiting to crush them.

Turned out that for anyone other than the Mankanshoku’s, if someone were to indulge in their surprisingly abundant food, they were going to put on a lot of weight, especially when it was being crammed down their throat at an alarmingly fast pace.

Regardless, there was no going back and changing what happened, so instead of sulking about her new weight, Ryuko decided instead to use it to her advantage and sweep away all of the grunts that dared to get in her way.

While the hefty girl was climbing her way through the echelon, Omiko took a keen interest in the young girl and decided to see what she was made of. Even after challenging Ryuko to a game of tennis, the blonde girl still managed to lose due to the fact that the black-haired girl managed to return even Omiko’s deadliest volley with just her belly alone. It was at that moment the sharp-toothed girl knew that she had to make Ryuko hers.

Over the next month, the scissor-wielding fatty managed to do quite a bit of damage to the school. Eventually, she got a little bored trying to draw Satsuki out, so she made use of her new body and decimated the members of the Sumo Club and became it’s leader. Considering she was still a capable fighter even with the added weight, it was a perfect match for Ryuko’s new aesthetic, as well as a suitable staging ground for Omiko to get what she wanted.

There were of course a countless number of challengers that wanted to get at the chubby girl, and now that she was officially a leader of a school sanctioned club, there was a plethora of people for Ryuko to completely flatten, so she never found herself bored. One day, the tennis player came by and challenged the black-haired girl for a rematch, only this time at sumo.

Ryuko of course accepted, thinking that she was going to win easily with how frail and stick-like the other girl was, but in just a few short minutes, Omiko utterly destroyed the chubby girl in a landslide victory, just like Ryuko had done to her.

Despite the overwhelming difference in size, the blonde girl used that to her advantage and managed to not only make use of her own body, but turn Ryuko’s against itself. The second the heavy girl fell to the ground, it was all over, and Omiko seized her long-awaited victory. From that point on, the pair were practically inseparable.

Most people believed that it was because they both respected each other for going toe to toe against each other in their respective fields and managing to pull out a surprise victory, but in reality, it was because Omiko had the fat girl wrapped around her finger like a glove, a really big and bulky glove.

Ever since Ryuko lost, the black-haired girl didn’t really know what to think. It was her first time losing since Satsuki, and being that it was to someone she had already beaten, the young girl felt like she wasn’t worthy enough to challenge Satsuki again. Over time, the chubby girl got more and more submissive to the point where the thought of taking the president of the school on didn’t even occur to her anymore. All that was left were thoughts about her girlfriend and how she could appease the small little stick that had beaten her.

“Oh Ryuko, aren’t you just the cutest thing ever!” Omiko cooed as she came up from behind Ryuko, giving the chubby girl’s ass a firm pinch as she giggled to herself with that sharp toothed grin of hers. It was exceptionally easy since she had caught the chubby girl just before her next Sumo match, so the only thing the black-haired girl was wearing was the bandages covering her boobs, her shoe-like geta, and the thick loin cloth that just barely managed to cover her crotch.

Ryuko just pouted and puffed out her cheeks as she looked back at the blond girl, her face blushing furiously as she raised one arm up against her massive bosom while the other stayed outstretched to the side.

“Oh, don’t worry, you know I’m only teasing. I’m just here to make sure that you have everything you need before you get into the ring.” Omiko cooed as she pulled the pinched skin towards her, letting it go only when it couldn’t go any further so she could watch it snap back into place like rubbery gelatin.

“I don’t need you babying me all the time. I’m a big girl and I can take care of myself.” Ryuko huffed as she pressed her arms against her breasts and wiggled her body from side to side.

“I know, I know. But can you blame me for worrying? I just don’t want to see my cutie patootie lose out there. After all, the only one who’s allowed to pin that bubble butt of yours to the ground is me.” The blonde girl replied in a low tone as she leaned in closer to the heavy girl’s ear.

Thoroughly rattled at this point, Ryuko shook her head and slapped her cheeks to try and calm herself before she had to go out in the next few minutes. The black-haired girl loved Omiko as much as she did her, but there were just some times where the other girl would take the whole mothering thing a little too far. She was alright with a little bit of teasing, but the way the sharp-toothed girl talked down to her made Ryuko feel like she was just an overgrown toddler, and she made sure to let her partner know that.

“You know I love you, but you keep treating me like I’m some helpless baby. My belt might look similar to a diaper, but that doesn’t mean it is you know.” Ryuko said, hoping to get Omiko to understand where she was coming from and maybe even get the young girl to ease up on the overprotectiveness. Unfortunately, all she did was make things even worse.

“Aw, you’re so cute when you try to be assertive!” The blonde girl gushed, proving Ryuko’s point about how little her partner saw her as despite the overwhelming difference in their sizes. It was ironic really. Now that the black-haired girl was the biggest she had ever been in her life, there was someone who looked at her and made her feel even smaller than ever.

Knowing there was going to be no reasoning with Omiko, the chubby girl let out a heavy sigh before turning around to head out into the ring. It was just about time for Ryuko to make her entrance, and if she’s learned anything from being the captain of the Sumo club over the last few months, she knew that the real battle began before she even stepped foot in the ring.

“Go get em tiger!” Omiko encouraged before giving Ryuko’s blubbery ass a firm smack, causing her entire body to jiggle as the shockwaves from the hit rippled throughout her body.

Ryuko looked back once again with a bright red blush on her face as she pouted before turning around and making her way out into the Sumo arena where her next opponent was waiting for her.

As Omiko watched the hefty girl’s body jiggle with every step it took, she started to think about what Ryuko said to her. The chubby girl was pretty spot on about the whole mothering thing, but that’s not what the blonde girl decided to focus on. Instead, what really caught her attention was what Ryuko said about diapers.

Just the thought of her big chubby boulder waddling around in some extra thick pampers to keep her from making a mess on the floor was just too adorable not to squeal at. Hell, it wasn’t even that hard to imagine. Like Ryuko said, her loincloth did make for a pretty good pass as a diaper, even if it didn’t have the absorbency of one.

Suddenly, a whole slew of thoughts rushed into Omiko’s head, filling her with a multitude of dastardly ideas and plots to turn the hefty girl into her big baby. As the puzzle pieces all fit together in her head, the blonde girl cracked a smile that only grew bigger the more a plan came into place. By the time she had basically figured out the skeleton of her plan, Omiko was grinning from ear to ear as she slowly slunk into the shadows of the waiting room.

A few days passed since Omiko’s rush of brilliance, and nearly all the pieces of her plan were in place. All she needed to do now was wait for her bouncy bubble butt to walk onto school grounds.

Like clockwork, Omiko looked over yonder at the closing gates, only to watch them suddenly burst open as Ryuko bulldozed through them. Following closely behind her was Mako, but since she was also in a rush, the brown-haired girl booked it towards the building in hopes that whatever punishment she was going to receive for being late would at least be lessened with every second saved.

Meanwhile, Ryuko took her sweet time walking up to the building now that she was on school grounds. There really wasn’t anything the staff could do about her anyways, so there was no penalty for missing the first few minutes, or even an entire period in general. Because of that, the black-haired girl was actually going to use that to her advantage and use the first part of her day to prove to Omiko that she was a big girl, and that she could wear the pants in the relationship just as well as her partner.  
It didn’t take the chubby girl long to locate the tennis player, spotting the blonde girl staring down at her from atop the school’s rooftop.

“Alright Ryuko, you’ve got this. All you have to do is show Omiko that you’re just as assertive as she is and she’ll start treating you more like an adult.” The young girl said to herself as she took some calming breaths. She also used those same breaths to steady her breathing, because the rush to get there had really taken its toll on her. One would think that she would have better stamina being a Sumo wrestler and all, but living with Mako somehow made her feel even fatter and more lethargic every day. 

Once the black-haired girl was ready, she put her game face on and started the trek up the stairs of the school to meet up with Omiko who was thankfully still waiting for the chubby girl at the top of the school. Thankfully it wasn’t actually the tippy top of the school where Satsuki was. Just thinking about scaling that ginormous tower tired the heavy girl out.

“So, how’s my bubble butt doing today? Come to double check that you’re ready for the day?” Omiko teased as she held a hand up to her mouth, giggling at her teasing while Ryuko just blushed and puffed out her cheeks like she always did.

However, Ryuko wasn’t about to let Omiko get into her head, not this time, so she quickly collected herself and calmed down so that she could talk to the blonde girl.

“Omiko, we need to talk.” The chubby girl stated as she stood up a little more prominently than before.

“Impressive. And here I was thinking that I was going to be doing most, if not all the talking as usual.” The thinner girl retorted, her tone piercing through all the layers of fat and making Ryuko blush once more.

“W-well, not this time. I uh, actually wanted to…I wanted to…” Ryuko stuttered, finding it a lot more difficult to be assertive than she thought it was going to be. With anyone else, the hefty girl would have had no problem, but Omiko just oozed this dominating aura that made Ryuko cower with her tail tucked between whatever space there is between her legs.

“Aw, is the big baby having trouble with her words?” The blonde girl teased as she bent down and held her knees.

“I-I’m not a baby!” Ryuko shouted as she clenched her fists and threw her arms to the side, her body jiggling violently as she did so.  
“Really? You sure seem to be acting like one.” Omiko continued to taunt. If there was anyone who knew how to press the chubby girl’s buttons, it was her.

“N-no I’m not!” The black-haired girl said a little shyer now, realizing that her actions might not have been helping her.

“I don’t know about that pumpkin. Just look at all that baby fat on you.” Omiko continued to tease as she walked over to the heavy girl, giving one of the many rolls on her body a few firm pokes to illustrate her point.

“I’m not a baby. I’m not a baby. I’m not a baby!” Ryuko shouted as she repeatedly stomped her foot on the ground, the overweight girl’s body jiggling with every stomp and only making her look like and overgrown toddler.

“Uh-oh! Sounds wike someone’s getting a wittle cwanky. I think it’s about time for the baby’s nap.” The blonde girl stated with an eerie smile before getting in just a little bit closer.

Before Ryuko could say or do anything, the black-haired girl found herself being hoisted up in the air by her girlfriend. Thanks to the Goku uniform she was wearing; it was simple for even someone as thin as her to lift the gargantuan girl off the ground without any issues at all.

When the black-haired girl realized she was being carried, she immediately ceased her tantrum and looked down at her girlfriend in confusion.

“Aw, did you just want mommy’s attention? It’s okay if that’s the case sweetie, I know you’re such a needy baby.” Omiko said in a motherly voice as she flipped the chubby girl in her arms into a bridal carry so she could see the big blusher’s face.

Ryuko didn’t know what to say. She had never felt so powerless in her life. She wanted to move, say something, do anything, but her entire being felt too small to oppose the other girl.

“Now let’s go get you changed into something a little more appropriate. We wouldn’t want people thinking you were a big girl, now do we?” The blonde girl cooed as she gave the chubby girl a little boop on the nose.

Still unable to respond, Ryuko just laid still in Omiko’s arms and let the blonde girl carry her back into the school and into an empty classroom that looked like it had been vacant for years. The tennis player had already scouted ahead for rooms that would be a perfect venue for her plan, so she knew there wasn’t going to be anyone to interfere in their intimate bonding time.

“This should do nicely.” Omiko said to herself as she walked further in and placed Ryuko down in the middle of the floor, the young girl immediately cracking her fingers before reaching below the fat girl’s skirt and pulling down her underwear.

“M-my panties!” Ryuko shrieked as she felt the thin piece of cloth being stripped from her bottom.

“Don’t worry Ryuko, mommy’s going to replace with a nice thick diapee in just a second.” Omiko stated as she tossed the underwear away, digging into her backpack right after and pulling out an extremely large and overly thick adult diaper with various baby block prints scattered all over it.

The chubby girl didn’t really know what to think about the childish undergarment. On one hand, she was impressed that they even made diapers for someone of her size, but on the other, she was totally shocked that her girlfriend was actually serious about putting her in something that looked like an actual baby would wear. It might have been better if it was plain white, but this diaper was so clearly made with the intent to make Ryuko look like a big fat baby.

This was all before the diaper was even unfolded. When Omiko finally opened it up, the black-haired girl was even more surprised at how massive it was. She had sort of hoped that there was no way the diaper was going to be able to fit around her, but the chubby girl should have known that her girlfriend wouldn’t have attempted this unless she had gotten one in her size.

After grabbing both of Ryuko’s legs and lifting them up, Omiko took the overly large undergarment and slid it all the way under the other girl’s butt and then some before setting the chubby girl’s hammocks back down onto the fluffy padding. Once that was done, the blonde girl reached into her bag once again, pulling out a bottle of baby powder and sprinkling a healthy coating of it all over Ryuko’s crotch and butt.

The pungent smell of the powder quickly filled the air, causing Ryuko to blush and fidget a bit as Omiko tried to finish the change. The other girl didn’t mind that though. She thought it was actually really adorable, and only reaffirmed the blonde girl of her decision to diaper the chubby girl. It was already clear that she was the one that wore the pants in the relationship, but now she was going to make sure everyone could see it too.

All that was left was to pull the front of the diaper up and secure it tightly with the tapes in the back, a process that Omiko made sure to do very slowly so she could savor the look on the chubby girl’s face as her womanhood was slowly stripped away. When the last tape was affixed firmly on the landing zone of the front of the diaper, Omiko gave the big baby an equally big smile as she ran her hand against the front of the plastic-backed undergarment.

“There we go! Doesn’t that just feel better?” The thin girl cooed as she gave the front of the thick diaper a few loving pats, causing some of the powder on the inside to puff out the sides in the process.

“I-I guess it is a lot comfier than my panties…” The now padded girl stuttered as she lightly wriggled in place, getting a feel for the thick padding as it crinkled loudly with her every movement. That last part was actually her favorite despite how it was a pretty obvious tell to someone nearby that she was diapered, but it’s siren sound was just so addictive, especially as she felt the fluffy diaper against her skin.

“Good girl. Now when school ends, you come directly to my place, understand?” Omiko commanded as she helped the chubby girl sit up on her tushy, the sound of the diaper crinkling drowning out the creaking of the wooden floor below them as all that weight was shifted into one spot.

“Y-yes…” Ryuko trailed off as her voice got lower and her thumb found its wat dangerously close to her mouth. She didn’t just look the part of a baby now; she was actually acting like one too.

“Yes what?” Omiko asked with a smile as she leaned in with her ear closer to the diapered girl’s mouth, hoping to hear a little more than just a simple yes come out of the big baby’s mouth now that her place was firmly cemented in stone.

“Yes…mommy.” The chubby girl finally said before inserting her thumb into her mouth, giving it, a few suckles as she averted her gaze from her girlfriend and directed it towards the floor instead.

Omiko smiled. “Oh, and you had better not take that diaper off to go potty. Either you go in your pants, or you don’t go at all, got it?”

“Yesh mommy.” Ryuko lisped from behind her thumb, her heart racing with adrenaline from how the blonde girl was treating her.  
“Good.”

With that, Omiko turned around and took her leave of the heavy girl, getting back to her regular schedule now that she had turned the feared sumo wrestler into her little play thing. She didn’t really care what Ryuko did now, so long as it didn’t involve her big baby removing her diaper. Whether she just stayed there the whole day or went to her classes, there was one thing for sure, and that was the fun the pair were going to have when the final school bell rang and released everyone.

The rest of the day, Ryuko didn’t go to a single one of her classes. The chubby girl just hid away in the parts of the school no one would go to so she could get used to her new underwear in peace. She debated taking it off now that the blonde girl was nowhere near her, but if today had taught Ryuko anything, it was that there was no way she could ever hope to go against her girlfriend.

With that in mind, the black-haired girl let out a sigh and just continued to waddle around the school all by her lonesome until the end of the day finally came. There was however one thing she needed to take care of before leaving to Omiko’s house.

Once the chubby girl was certain that every last person other than Satsuki and her entourage were gone, she quickly rushed out of the school and towards the gate as fast as she could. Sadly, just before she reached the gate, Ryuko suddenly stopped when she felt her stomach gurgling. She had been holding in a poop for about a week now due to her diet, and while she did feel the need to go a little earlier, she refused to since it would have meant having to spend most of the day in a messy diaper.

Now that there was no other choice though, the black-haired girl got into a squatting position and took a deep breath before clenching her fists and holding her arms up to her chest as she strained to push out the massive load that was waiting to be released.

Normally, it would take a bit to push it out, but because Ryuko had been holding it for so long, the foul-smelling mush just exploded into the back of her diaper, instantly staining it brown as it bulged out the back and spread throughout the rest of the crinkly undergarment. The second that cork was released, the heavy girl let out a very relieved sigh as she relaxed her body and just let her butt release the slimy sludge unhindered. Not even the disgusting feeling of her own filth bubbling and splattering against her privates was enough to faze her, she was just happy that she was finally able to relive herself after all those hours of holding it.

When she was finished though, the chubby girl did feel a bit of shame, and even some regret as she looked back at the bulging mess in the seat of her diaper. Her skirt barely covered it when it was dry, but now the babyish undergarment was exposed for the entire world to see, not to mention smell. The worst part of it was that it actually felt really nice, but it was hard to enjoy it out in the open like this, even though there wasn’t another person within miles of her.

With her pants thoroughly soiled and her dignity practically in the gutter at this point, Ryuko gulped and hoisted up her smelly pampers before waddling out the front gate of Honnōji academy with her full diaper squishing and squelching with every step. Hopefully Omiko would take pity on the chubby girl and change her out of her stinky mess when she met up with her, cause if not, something told the diapered girl that her diaper was going to get a whole lot messier as her stomach let out a resounding growl.


End file.
